[Ability of leukocyte reduction filters to remove fat particles from blood in experimental models simulating blood salvage in orthopedic surgery].

BACKGROUND

Salvaged autologous blood in orthopedic surgery may contain tissular debris such as fat particles (FP), possibly increasing the risk of fat embolism after bone surgery. Therefore, this study was initiated to ascertain the capacity of leukocyte filters to remove FP using in vitro models.

METHODS

All experiments were performed in triplicate using donor blood bags within 15 days of their donation. Five different olive oil volumes were added to blood to obtain 5 oil concentrations (1% to 5%), and blood was subsequently filtered through a PureCell (Pall Biomedical, Portsmouth, UK) leukocyte-reduction filter. In another set of experiments, 5 different oil volumes (1, 2.5, 5, 7.5 or 10 mL) were injected into the line during filtration of oil-free blood. In addition, 3 preparations of blood supplemented with 5% oil were processed in the autotransfusion device OrthoPAT (Haemonetics Corp, Braintree, MA, USA), and the obtained red cell concentrate was subsequently filtered through PureCell. We collected samples for cell counting and analysis and FP detection with a Pentra 120 Retic (ABX, Montpellier, France) flow cytometer.

RESULTS

Specific signals corresponding to FP were clearly detected in the white blood cell scattergrams yielded by the cytometer for oil supplemented blood. PureCell removed FP up to an oil concentration of 3% or up to an injected oil volume of less than 10 mL. Addition of a filtration step through a PureCell filter after blood washing by the OrthoPAT device completely removed FP.

CONCLUSIONS

Leukocyte filters seem to be useful for removing FP from unprocessed blood with a low degree of fat contamination (less than 10 mL) and to complete FP removal from processed blood. Therefore, using a leukocyte filter in the patient's line should contribute to improving the safety of perioperative autologous blood salvage.